Resistivity reconstructing method utilizing linear doublecurl equation to proceed magneto thermo-acoustic imaging

Abstract

The invention discloses a resistivity reconstructing method by utilizing linear double curl equation to proceed magneto-thermo-acoustic imaging. The method includes the following steps: firstly, acquiring thermo-acoustic signals of conductive objects subjected to circular tomography; secondly, acquiring thermo-acoustic source distribution on an arbitrary fault surface of the conductive object by utilizing a time reversal algorithm according to an acoustic pressure wave equation of magneto-thermo-acoustics; thirdly, drawing forth a vector potential to assume an initial value of the resistivity of the conductive object through the current continuity theorem; fourthly, solving a vector potential spatial component with the initial value of the resistivity, and then substituting the solved spatial component of vector electric potential to the thermal-acoustic source distribution to acquire an updated conductivity distribution; fifthly, comparing the updated resistivity with a resistivity set with the initial value, checking whether a given relative error is met, if yes, confirming that the updated resistivity is the solved resistivity, if not, backing to the third step to perform iterating, and using the updated resistivity as an initial resistivity to further solve the updated resistivity, thereby acquiring the conductivity distribution of the conductive object.

Description

technical field [0001] The invention relates to a method for reconstructing resistivity images, in particular to a method for reconstructing resistivity using linear double-curl equations for magneto-thermoacoustic imaging. Background technique [0002] At present, the sensitivity and spatial resolution of traditional electrical impedance imaging technology are not high, mainly because electrical impedance imaging usually uses electromagnetic waves with low frequency as excitation. Since the wavelength is much larger than the imaging object, the electromagnetic field detection contrast is high, but the resolution is low. Needless to say, a single field has its physical limitations. Therefore, multi-physics imaging technology has received more and more attention, that is, one physical field acts on biological tissue and converts it into another physical field for detection. One physical field provides resolution, and the other provides contrast. , achieving simultaneous impr...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the deficiency that the existing magneto-thermoacoustic imaging method cannot provide the resistivity distribution, and propose a reconstruction method of using the linear double-curl equation to reconstruct the resistivity distribution of the thermoacoustic source distribution

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